One of the dead women was a founder of the Kurdistan Workers Party — or PKK — a Kurdish separatist group that has waged a guerrilla war against Turkey since 1984. The other two were Kurdish activists who may well have died because they were simply in the wrong place at the wrong time.

There were competing theories over who was responsible, and outraged Kurds poured into the street in Paris, blaming Turkey. Officials there said the killings were likely a dispute among Kurds, perhaps intended to derail new peace talks between the government and the PKK’s jailed leader, or to settle a score.

But these were theories. The evidence spoke only to a well-planned job.

“No hypothesis can be excluded at this stage’’ about the motive, said Agnes Thibault-Lecuivre, a spokeswoman for the Paris prosecutor’s office. Visiting the crime scene on Thursday, Interior Minister Manuel Valls called the killings ‘‘intolerable’’ and said they were ‘‘without doubt an execution.’’

The shootings took place in the gritty 10th district of the city, near the Gare du Nord railroad station, in a working-class immigrant neighborhood of Turkish kebab shops and African hair salons. The killings prompted outrage, raised fears of violent revenge violence, and opened a new chapter in the often murky annals of Kurdish exile life.

The bodies were found about 2 a.m. inside the Kurdish Information Center that is used to promote Kurds’ political and cultural agendas. Someone would have to have known the office was there; there was no plaque outside. And the front door could only be opened with a digital code — or if the occupants buzzed someone in, the manager of the center, Leon Edart, told reporters.

That possibility led to many questions. Did the women know their killer? Did the killer slip in behind a welcomed guest? An organization called the Federation of Kurdish Associations in France, representing many of the estimated 150,000 Kurdish exiles in the country, added to the intrigue, saying in a statement that the victims might have been killed with weapons equipped with silencers.

“Why anyone would want to do this is unclear,’’ said Rusen Werdi, a Kurdish lawyer who knew two of the women. ‘‘It was an ambush.’’

The bodies, she said, were discovered after friends became concerned about the women because cellphone calls had gone unanswered and none of them had returned home.

Thibault-Lecuivre said the antiterrorism department of the prosecutor’s office would oversee the investigation.

The authorities confirmed the identity of two of the victims: Leyla Soylemeza, a young Kurdish activist, and Fidan Dogan, the head of the Kurdish Information Center and a representative of the Kurdistan National Congress. News media reports said the third woman was Sakine Cansiz, a founder of the Kurdistan Workers’ Party.

But for all the intrigue, Werdi said, it appeared that the target was Cansiz, a founding member of the PKK. The other two victims may well have been killed because they were there with her.

Werdi said that at least one of the women had been under surveillance by the French police because of her activism. She said that Cansiz had been keeping a low profile in recent months and it was rare for her to be at the information center.

The PKK is no stranger to infighting and internal strife. Hurriyet, a Turkish daily newspaper, said Cansiz was ‘‘known for her opposition to the alleged head of the PKK’s armed wing, Syrian citizen Ferman Hussein.’’

Cansiz had been in Paris since 2007 after the authorities in Germany arrested and briefly held her before turning down a Turkish request for her extradition.

Kurdish activists said she was very close to Abdullah Ocalan, the head of the PKK, who has been jailed since 1999. Cansiz was imprisoned in Turkey in 1979 and freed in 1991, after which they said she became active in the organization. She played a leading role garnering financial and political support for the Kurdish cause in Europe.